The Effectiveness of Custom ACL Bracing in Adolescent Populations

ABSTRACT Introduction Functional anterior cruciate ligament (ACL) orthoses protect the knee from further injury by preventing anterior tibial translation and valgus moments at the joint. Through contact loading, the anterior tibial pads on the orthosis provide a posteriorly directed force to minimize anterior strain to the healing ACL graft. Objective The purpose of this study was to determine how effective custom functional ACL bracing is in preventing anterior tibial translation. Study Design Observational study. Methods The contact pressures of custom ACL orthoses exerted along the tibia were replicated in 22 patient-specific pediatric finite element models. Previously developed, nonbracing knee models that have been validated in accurately predicting anterior tibial translation were utilized to determine how effective this orthosis design is in preventing anterior joint translations when subject to Lachman and pivot shift test loading conditions. Results For the Lachman test, the anterior tibial translations decreased from 5.53 mm, 6.53 mm, and 7.54 mm to 4.82 mm, 5.60 mm, and 6.58 mm. The pivot shift test experienced a decrease from 4.38 mm to 3.64 mm when the anterior tibial pad contact loads were applied to the models. The custom ACL knee orthosis provides a significant ( P < 0.05) resistance to anterior tibial translation compared with the nonbracing models for both loading conditions. Conclusions The utilization of finite element technology makes it possible to assess knee orthosis biomechanics in a manner that is difficult or cannot be assessed in a clinical setting. Custom functional ACL knee orthoses provide a significant resistance to anterior tibial displacement. Clinical Relevance Statement Understanding the biomechanical impact knee orthoses have in protecting the healing ACL graft can provide clinicians with the opportunity to prescribe the best orthosis that will significantly minimize the risk of reinjury and improve patient outcomes and quality of life.